A tunable Ti3C2T x Multifunctional protective coating enhanced by planar arrangement of / GO heterojunction and preparation method thereof

Abstract

This specification is about a tunable Ti3C2T x A multifunctional protective coating enhanced by flat arrangement of / GO heterojunctions and a preparation method thereof, relating to the technical field of surface engineering, comprises: S1: weighing epoxy electrophoretic resin and deionized water, mixing them evenly and standing them to fully mature, dividing the matured solution into two parts to obtain solution A and solution B; S2: adding fully protonated Ti3C2T x to solution A; add single-sided protonated GO to solution B, stir them at room temperature for 1 hour, and obtain mixed solution A and mixed solution B; S3: pour mixed solution A and mixed solution B into the epoxy electrophoresis tank in sequence for electrophoretic deposition; S4: after the deposition is completed, rinse the residual liquid resin on the surface of the coating with running water, and cure it at 170-210℃ for 85-100min to obtain a multifunctional protective coating.

Description

Technical Field

[0001] This specification relates to the field of surface engineering technology, in particular to a Ti3C2T x Multifunctional protective coating enhanced by planar arrangement of / GO heterojunction and its preparation method. Background Art

[0002] Numerous studies have shown that two-dimensional materials (such as Ti3C2T x , GO, MoS2, etc.) with resin coatings can significantly improve the corrosion resistance and tribological properties of the resin coating, thereby effectively extending the service life of major equipment. At the same time, mature surface micro-nanoscale modification technologies have also solved the problem of easy agglomeration of two-dimensional materials in resins, and significantly improved the interfacial affinity between two-dimensional materials and resins. However, the improvement of the tribological and corrosion resistance of the coating by the two-dimensional materials randomly oriented and distributed in the resin is far lower than the theoretical model and hypothesis. The most important point lies in the distribution orientation of the two-dimensional flakes in the resin coating. For tribological performance, the orientation of two-dimensional materials that are parallel to the load application direction or can be projected in the load application direction is harmful to the friction reduction process of the resin material. Because this orientation will make it difficult for the two-dimensional material to slip during the friction process, and even hinder the slip of other parts, thereby increasing friction. Regarding corrosion resistance, when the 2D flakes are perpendicular to the coating surface, the shielding effect disappears, and the filler utilization rate is 0%. When they are randomly distributed, the filler utilization efficiency ranges from 0 to 100%, and the shielding effect on the corrosive medium is uneven across the coating, making it easier for the corrosive medium to penetrate through weak points. When the 2D material is distributed parallel to the coating surface (i.e., perpendicular to the diffusion direction of the corrosive medium), the filler utilization efficiency reaches 100%, creating a continuous shield against corrosive ions and achieving protection close to theoretical predictions. Currently, researchers have used methods such as electric field manipulation, magnetic field manipulation, and mechanical extrusion / stretching to precisely achieve the planar arrangement of 2D materials in resin coatings. Electric field manipulation offers advantages such as time-saving, simple equipment, easy operation, and avoidance of filler structure damage. However, the friction and corrosion protection effects of simply aligning a specific type of 2D material in a resin have been less than satisfactory. This is primarily due to the following reasons: (1) interlayer slip of the 2D material in the cured coating is limited; and (2) corrosion current easily propagates through the regularly arranged 2D material.

[0003] The incommensurate contact between heterojunctions is the theoretical basis for structural superlubricity. A perpendicular heterojunction, also known as a van der Waals heterojunction, is formed by stacking two dissimilar two-dimensional materials, with the interlayer interaction being van der Waals forces. The stacked two 2D materials are in a state of complete lattice mismatch, which weakens the atomic interactions between the two materials. Especially during relative sliding, contact points are concentrated at specific atomic locations, rather than over a large area, resulting in a dramatic reduction in friction. Simultaneously, a microcapacitor forms between the two 2D materials in the van der Waals heterojunction, blocking further propagation of the corrosion current. This capacitor effect prevents ions in the corrosive medium from crossing the heterojunction interface, effectively inhibiting the corrosion process. Considering the aforementioned drawbacks and limitations of 2D material-reinforced resin coatings, the universal application of van der Waals heterojunctions in epoxy coatings holds great promise, but relevant research has yet to be reported. Summary of the Invention

[0004] This specification provides a tunable Ti3C2T x A multifunctional protective coating reinforced by a planar arrangement of GO (TG) / GO (TG) heterojunctions and its preparation method. This multifunctional protective coating can effectively address the friction, corrosion, or tribo-corrosion coupled damage challenges faced by high-end precision friction (transmission) components and systems, such as military aviation spherical bearings and offshore wind power.

[0005] The first aspect of the present invention provides a Ti3C2T x The method for preparing a multifunctional protective coating enhanced by a planar arrangement of a GO / GO heterojunction comprises:

[0006] S1: Weigh epoxy electrophoretic resin and deionized water in a mass ratio of 1:2, mix the epoxy electrophoretic resin and deionized water evenly, and let stand for 90-120 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution, and divide the matured solution into two parts to obtain solution A and solution B in a mass ratio of 9-11:4-6;

[0007] S2: Adding fully protonated Ti3C2T x To solution A, the fully protonated Ti3C2T x The mass ratio of single-sided protonated graphene oxide (GO) to epoxy electrophoretic resin is 1-2:100; single-sided protonated graphene oxide (GO) is added to solution B, wherein the mass ratio of single-sided protonated GO to epoxy electrophoretic resin is 0.5-1:100, and the mixtures are stirred at room temperature for 1 hour to mix them uniformly, thereby obtaining mixed solutions A and B;

[0008] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min, and pour the mixed solution B into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min;

[0009] S4: After the deposition is completed, the residual liquid resin on the surface of the coating is washed away with running water, and the coating is cured at 170-210°C for 85-100 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

[0010] In some embodiments, the fully protonated Ti3C2T x Replaced with fully protonated GO, replaced with single-sided protonated Ti3C2T x , a multifunctional protective coating enhanced by G / T heterojunction flat arrangement is obtained in S4; including:

[0011] S1: Weigh epoxy electrophoretic resin and deionized water in a mass ratio of 1:2, mix the epoxy electrophoretic resin and deionized water evenly, and let stand for 90-120 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution, and divide the matured solution into two parts to obtain solution A and solution B in a mass ratio of 9-11:4-6;

[0012] S2: Add fully protonated GO to solution A, wherein the mass ratio of the fully protonated GO to the epoxy electrophoretic resin is 1-2:100; add single-sided protonated Ti3C2T x To solution B, the single-sided protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin is 0.5-1:100, and the mixture is stirred at room temperature for 1 hour to be uniformly mixed to obtain mixed solution A and mixed solution B;

[0013] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min, and pour the mixed solution B into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min;

[0014] S4: After the deposition is completed, the residual liquid resin on the surface of the coating is washed away with running water, and the coating is cured at 170-210°C for 85-100 minutes to obtain a multifunctional protective coating with enhanced G / T heterojunction flat arrangement.

[0015] The second aspect of the present specification provides a multifunctional protective coating prepared by the above method, wherein the thickness of the multifunctional protective coating is 30-100 μm, and the multifunctional protective coating is a multifunctional protective coating enhanced by a T / G heterojunction flat arrangement, and comprises the following components in percentage by mass: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated Ti3C2T x and 0.17%-0.36% single-faced protonated GO.

[0016] In some embodiments, the thickness of the multifunctional protective coating is 30-100 μm, and the multifunctional protective coating is a multifunctional protective coating enhanced by a G / T heterojunction flat arrangement, and comprises the following components by mass percentage: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated GO, and 0.17%-0.36% single-sided protonated Ti3C2T x .

[0017] This specification has the following beneficial effects.

[0018] (1) This specification first proposes to use the Marangoni effect to achieve single-sided protonation modification of two-dimensional materials. Single-sided protonation modification refers to protonating one side of a two-dimensional material to make it positively charged, while the other side retains its original properties. This specification cleverly uses three liquids with different surface tensions to prepare GO or Ti3C2T x The culture dish contains a layered solution, the lower layer is deionized water containing PEI, and the upper layer is n-hexane. x ) was dissolved in isopropanol and dropped into the above layered solution. Due to the surface tension gradient, GO or Ti3C2T x A single layer of GO or Ti3C2T will spontaneously form at the delamination point of the above-mentioned delamination solution. x The lower surface of the membrane is immersed in PEI solution, and the upper surface is immersed in n-hexane to achieve GO sheet or Ti3C2T x The lower surface of the sheet is modified by amino to load -NH2. Then the GO or Ti3C2T with only one side loaded with -NH2 is x -NH2 is converted to -NH3 by hydrogenation of HCl solution + or -NH4 +, thus completing the protonation modification of a single surface of a two-dimensional material. This single-surface protonation modification method has not been reported in any literature or patents, and multiple characterization methods have confirmed its success and effectiveness. It is foreseeable that this single-surface protonation modification method can be extended to any two-dimensional material that meets this principle.

[0019] (2) The formation of heterostructures in the multifunctional protective coating of this specification requires an electrophoretic deposition process. Taking the T / G heterojunction as an example, a fully protonated two-dimensional material Ti3C2T is added to the epoxy electrophoretic resin. x Ti3C2T x The surface is positively charged, and due to the electric field force, Ti3C2T x They tend to rotate to the direction perpendicular to the electric field line and repel each other while moving toward the cathode. When single-sided protonated GO is added, most of the GO will be inserted into Ti3C2T x With Ti3C2T x The positively charged surface of GO will simultaneously interact with Ti3C2T x Repulsion occurs, causing its uncharged surface to approach Ti3C2T infinitely. x To form a T / G heterojunction, and to arrange it perpendicular to the electric field lines in the resin, that is, flat on the deposition substrate. The principle of the ordered self-assembly process of the G / T heterojunction is the same as that of the ordered self-assembly process of the T / G heterojunction, and a T / G type heterojunction or a G / T type heterojunction can be constructed in the resin according to needs. There is no literature or patent report on the self-assembly and flat arrangement method of the heterojunction, and a variety of characterization methods have confirmed that the method is successful and effective. Due to the uniform flat arrangement of the heterojunction in the coating, its non-commensurate contact characteristics, excellent mechanical properties, corrosion ion barrier effect, etc. can greatly improve the tribological properties and corrosion resistance of the resin substrate. It is foreseeable that this single-sided protonation modification method can be extended to any two-dimensional material that conforms to this law.

[0020] (3) The multifunctional protective coating of this specification has good adhesion to substrates such as aluminum alloy, beryllium bronze, and steel, and has excellent tribological and corrosion resistance properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the theoretical basis for the rotation of two-dimensional nanosheets in an electric field and the subsequent heterojunction formation and planar alignment; Figure 1 include Figure 1 a. Figure 1 b and Figure 1 c, where Figure 1 a shows the fully protonated Ti3C2T xand the rotation and motion trajectory of fully protonated GO in an electric field; Figure 1 b shows the self-assembly process of T / G heterojunction and G / T heterojunction in an electric field; Figure 1 c shows a tunable Ti3C2T x Multifunctional protective coating enhanced by planar arrangement of / GO heterojunction and its heterojunction microstructure.

[0022] Figure 2 include Figure 2 a. Figure 2 b and Figure 2 c, where Figure 2 a shows the delamination phenomenon of PEI solution and n-hexane (n-hexane contains only oil-soluble shikonin, which appears red) and the spontaneous film formation of GO sheets at the delamination point; Figure 2 b shows the scanning electron microscope image of the GO monolayer film obtained by silicon wafer and its corresponding energy spectrum; Figure 2 c shows the Ti3C2T x Scanning electron microscope image of the single-layer film and its corresponding energy spectrum.

[0023] Figure 3 The flat arrangement of the T / G heterojunction enhanced multifunctional protective coating is shown in the nanoscale thin film after focused ion beam cutting (FIB cutting) and ion thinning, and the flatly arranged T / G heterostructure is observed using high-resolution transmission electron microscopy (HR-TEM).

[0024] Figure 4 Zeta potential values ​​for three different samples are shown.

[0025] Figure 5 Shown are the full X-ray photoelectron spectra of three different samples.

[0026] Figure 6 The flat arrangement of the G / T heterojunction enhanced multifunctional protective coating is shown in the nanoscale thin film after focused ion beam cutting (FIB cutting) and ion thinning, and the flatly arranged G / T heterostructure is observed using high-resolution transmission electron microscopy (HR-TEM).

[0027] Figure 7 GO or Ti3C2T according to some embodiments of the present invention x Schematic diagram of the single-sided protonation process.

[0028] Figure 8 The evolution curves of the friction coefficient of five coatings over time are shown.

[0029] Figure 9 The average friction coefficient and average wear rate of the five coatings are shown.

[0030] Figure 10 Log(Rc) values ​​for five coatings are shown. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by this specification easy to understand, this specification is further explained below in conjunction with specific implementation methods.

[0032] In this specification, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art.

[0033] In this specification, the type of epoxy electrophoretic resin is not particularly limited, and any type known to those skilled in the art and meeting the above requirements may be used. In the specific examples of this specification, the epoxy electrophoretic resin was purchased from Jiangxi Gaojie Technology Co., Ltd.

[0034] Some embodiments of this specification provide a tunable Ti3C2T x A method for preparing a multifunctional protective coating enhanced by planar arrangement of a / GO (TG) heterojunction includes the following steps.

[0035] S1: Weigh epoxy electrophoretic resin and deionized water in a mass ratio of 1:2, mix the epoxy electrophoretic resin and the deionized water evenly, and let stand for 90-120 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution, and divide the matured solution into two parts to obtain solution A and solution B in a mass ratio of 9-11:4-6.

[0036] In some embodiments, the mass ratio of epoxy electrophoretic resin to deionized water may be 1:1.7-1:2.3. In some embodiments, the mass ratio of epoxy electrophoretic resin to deionized water may be 1:1.8-1:2.2. In some embodiments, the mass ratio of epoxy electrophoretic resin to deionized water may be 1:1.9-1:2.1. In some embodiments, the standing time may be 60-180 minutes. In some embodiments, the standing time may be 70-160 minutes. In some embodiments, the standing time may be 80-140 minutes.

[0037] S2: Adding fully protonated Ti3C2T x To the solution A, the fully protonated Ti3C2T x The mass ratio of the single-sided protonated graphene oxide (GO) to the epoxy electrophoretic resin is 1-2:100; single-sided protonated graphene oxide (GO) is added to the solution B, and the mass ratio of the single-sided protonated GO to the epoxy electrophoretic resin is 0.5-1:100, and the mixtures are stirred at room temperature for 1 hour to obtain mixed solutions A and B.

[0038] In some embodiments, fully protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin may include 0.3-5:100. In some embodiments, the fully protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin may include 0.4-4:100. In some embodiments, the fully protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin may include 0.5-3:100. In some embodiments, the fully protonated Ti3C2T x The mass ratio of single-sided protonated GO to epoxy electrophoretic resin may include 0.8-2:100. In some embodiments, the mass ratio of single-sided protonated GO to epoxy electrophoretic resin may include 0.1-3:100. In some embodiments, the mass ratio of single-sided protonated GO to epoxy electrophoretic resin may include 0.2-2:100. In some embodiments, the mass ratio of single-sided protonated GO to epoxy electrophoretic resin may include 0.3-1.5:100. In some embodiments, fully protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin to the epoxy electrophoretic resin may be 0.4-1.2:100.

[0039] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min, and pour the mixed solution B into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0040] In some embodiments, the voltage may include 70-120V. In some embodiments, the voltage may include 80-110V. In some embodiments, the voltage may include 90-100V. In some embodiments, the first duration may include 1-5 minutes. In some embodiments, the first duration may include 2-4 minutes. In some embodiments, the first duration may include 2-3 minutes. In some embodiments, the second duration may include 0.5-3 minutes. In some embodiments, the second duration may include 0.7-2 minutes. In some embodiments, the second duration may include 0.8-1.5 minutes.

[0041] S4: After the deposition is completed, the residual liquid resin on the surface of the coating is washed away with running water, and the coating is cured at 170-210°C for 85-100 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

[0042] In some embodiments, the curing temperature may include 150-240°C. In some embodiments, the curing temperature may include 160-230°C. In some embodiments, the curing temperature may include 160-220°C. In some embodiments, the curing time may include 60-150 minutes. In some embodiments, the curing time may include 70-130 minutes. In some embodiments, the curing time may include 80-110 minutes. The higher the curing temperature, the shorter the curing time. For example, when the curing temperature is 190°C, the curing time is 90 minutes. For another example, when the curing temperature is 240°C, the curing time is 60 minutes.

[0043] For the current example and the following other examples and comparative examples, the following descriptions are provided regarding the coating and residual liquid resin. The coating refers to the coating deposited on the cathode of the epoxy electrophoresis tank. The residual liquid resin refers to the undeposited epoxy electrophoresis resin solution on the coating surface.

[0044] This specification provides a multifunctional protective coating that combines low friction, high wear resistance, and high corrosion resistance. This multifunctional protective coating can effectively address the friction, corrosion, or tribo-corrosion coupled damage challenges faced by high-end precision friction (transmission) components and systems, such as military aviation spherical bearings and offshore wind power.

[0045] In some embodiments, the fully protonated Ti3C2T x The preparation process includes the following steps: x and polyethyleneimine (PEI) were ultrasonically dispersed into 100 mL of deionized water to obtain Ti3C2T x solution and PEI solution. x Few-layer Ti3C2T x , the Ti3C2T x The thickness of the Ti3C2T is 0.1-1μm. x The diameter of the flakes is 20-30 μm, and the Ti3C2T x The purity of the PEI solution is 99.99%. x The reaction product was centrifuged and washed several times with ethanol and deionized water. A 1 mol / L HCl solution was added to the reaction product, and the reaction product was magnetically stirred at room temperature for 10-15 hours, centrifuged and washed several times with ethanol and deionized water, and freeze-dried to obtain the fully protonated Ti3C2T x .

[0046] In some embodiments, the preparation process of the single-sided protonated GO comprises the following steps: PEI is ultrasonically dispersed in deionized water, with the mass volume ratio of the PEI to the deionized water being 6-8 mg:2-3 mL, to obtain a PEI solution. GO is ultrasonically dispersed in 8-12 mL of isopropanol, with the mass volume ratio of the GO to the isopropanol being 45-55 mg:8-12 mL, to obtain a GO solution. The PEI solution is poured into the bottom of a culture dish, and an n-hexane solution is gradually added dropwise to the culture dish. A clear stratification occurs at the interface between the PEI solution and the n-hexane solution, and the GO solution is then gradually added dropwise to the culture dish; the mixture is allowed to stand at room temperature for 12 hours, and the GO film at the stratification is removed using a silicon wafer. The GO film is washed by multiple centrifugation with ethanol and deionized water, and a 1 mol / L HCl solution is added. The product is magnetically stirred at room temperature for 5-8 hours to obtain a product. After stirring, the product is washed by multiple centrifugation with ethanol and freeze-dried to obtain the single-sided protonated GO.

[0047] Regarding the implementation of the preparation process of single-sided protonated GO, there are the following embodiments. In some embodiments, the mass volume ratio of PEI to deionized water may include 6-8 mg:1-10 mL. In some embodiments, the mass volume ratio of GO to isopropanol may include 45-55 mg:5-20 mL. In some embodiments, the standing time may include 6-20 h. In some embodiments, the concentration of the HCl solution may include 0.3-3 mol / L. In some embodiments, a stirring rod or oscillator can be used instead of magnetic stirring. In some embodiments, the stirring time may include 3-12 h. In some embodiments, glass sheets, fresh mica sheets, etc. can be used instead of silicon sheets to fish out the film.

[0048] In some embodiments, the n-hexane solution is n-hexane. For example, the n-hexane solution is analytical grade n-hexane. In some embodiments, the n-hexane solution is a n-hexane solution in which shikonin is dissolved. In some embodiments, the n-hexane solution is a solution formed by mixing n-hexane with other water-insoluble organic substances.

[0049] In the above technical solution, the single-sided protonation is to perform single-sided protonation treatment on GO, that is, one side of the GO two-dimensional sheet is protonated to make it positively charged, while the other side still retains its original properties.

[0050] In some embodiments, in S3, the conductive block serves as the cathode in the electrophoretic deposition process, and the positively charged epoxy electrophoretic resin and the heterojunction are deposited on the cathode to form a coating. The conductive block is any conductive block material. The conductive block includes but is not limited to conductive metals, aluminum alloys (7075 aluminum alloys), titanium alloys, steel, and beryllium bronze. The conductive block needs to be pretreated. The pretreatment includes: sandblasting, grinding, or micro-arc oxidation of the conductive block to obtain a roughness of Ra∈[0.3,0.7] of the conductive block, ultrasonic cleaning with anhydrous ethanol, wiping with a dust-free cloth, and drying to obtain the pretreated conductive block for use.

[0051] In some embodiments, in S3, the conductive block serves as a cathode in the electrophoretic deposition process. The conductive block comprises at least one of a conductive metal, an aluminum alloy, a titanium alloy, a steel, or a beryllium bronze. The conductive block needs to be pretreated. The pretreatment includes: sandblasting, polishing, or micro-arc oxidation of the conductive block to make the roughness of the conductive block Ra∈[0.3,0.7], ultrasonically cleaning with anhydrous ethanol, wiping with a dust-free cloth, and drying to obtain the pretreated conductive block for use.

[0052] In some embodiments, the fully protonated Ti3C2T x Replaced with fully protonated GO, the single-sided protonated GO was replaced with single-sided protonated Ti3C2T x In said S4, a multifunctional protective coating enhanced by a flat arrangement of a G / T heterojunction is obtained, which includes the following steps.

[0053] S1: Weigh epoxy electrophoretic resin and deionized water in a mass ratio of 1:2, mix the epoxy electrophoretic resin and deionized water evenly, and let it stand for 90-120 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution, and divide the matured solution into two parts to obtain solution A and solution B in a mass ratio of 9-11:4-6.

[0054] S2: Add fully protonated GO to solution A, wherein the mass ratio of the fully protonated GO to the epoxy electrophoretic resin is 1-2:100; add single-sided protonated Ti3C2T x To solution B, the single-sided protonated Ti3C2T x The mass ratio of the epoxy electrophoretic resin is 0.5-1:100, and the mixture is stirred at room temperature for 1 hour to be uniformly mixed to obtain mixed solution A and mixed solution B.

[0055] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min, and pour the mixed solution B into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0056] S4: After the deposition is completed, the residual liquid resin on the surface of the coating is washed away with running water, and the coating is cured at 170-210°C for 85-100 minutes to obtain a multifunctional protective coating with enhanced G / T heterojunction flat arrangement.

[0057] In some embodiments, the preparation process of the fully protonated GO includes the following steps. Equal masses of GO and PEI are ultrasonically dispersed into 100 mL of deionized water to obtain a GO solution and a PEI solution. The GO is a single-layer GO, the thickness of the single-layer GO is 0.3-0.6 nm, the diameter of the single-layer GO is 10-20 μm, and the purity of the single-layer GO is 99.99%. The PEI solution is added to the GO solution, and the reaction product is obtained by magnetic stirring at room temperature for 20-28 hours. The reaction product is washed by multiple centrifugation with ethanol and deionized water. 1 mol / L HCl solution is added to the reaction product, magnetically stirred at room temperature for 10-15 hours, washed by multiple centrifugation with ethanol and deionized water, and finally freeze-dried to obtain fully protonated GO.

[0058] In some embodiments, the single-sided protonated Ti3C2T x The preparation process includes the following steps: ultrasonically dispersing PEI into deionized water, wherein the mass volume ratio of the PEI to the deionized water is 6-8 mg: 2-3 mL, to obtain a PEI solution. x Ultrasonic dispersion into isopropanol, the Ti3C2T x The mass volume ratio of the isopropanol is 45-55 mg:8-12 mL to obtain Ti3C2T x The Ti3C2T x Few-layer Ti3C2T x , the Ti3C2T x The thickness of the Ti3C2T is 0.1-1μm. x The diameter of the flakes is 20-30 μm, and the Ti3C2T x The purity of the Ti3C2T4 was 99.99%. The PEI solution was poured into the bottom of the culture dish, and the n-hexane solution was gradually added dropwise to the culture dish. The interface between the PEI solution and the n-hexane solution showed obvious stratification, and then the Ti3C2T4 x The solution was gradually added dropwise to the culture dish; it was allowed to stand at room temperature for 12 hours, and the Ti3C2T x The film was removed. The Ti3C2T was washed with ethanol and deionized water several times by centrifugation. x film; adding a 1 mol / L HCl solution and magnetically stirring at room temperature for 5-8 hours to obtain a product. After stirring, the product was washed with ethanol by centrifugation several times, and finally freeze-dried to obtain the single-sided protonated Ti3C2Tx of nanosheets.

[0059] Single-sided protonated Ti3C2T x The preparation process of Ti3C2T can be implemented in the following manner. In some embodiments, the mass volume ratio of PEI to deionized water can include 6-8 mg: 1-10 mL. In some embodiments, Ti3C2T x In certain embodiments, the HCl solution may be stirred at room temperature for 2-3 hours. In certain embodiments, the HCl solution may be stirred at room temperature for 2 hours. In certain embodiments, the HCl solution may be stirred at room temperature for ...

[0060] Using the above technical solution, the single-sided protonation is to x Single-sided protonation treatment is performed on Ti3C2T x One side of the two-dimensional sheet is protonated to make it positively charged, while the other side retains its original properties.

[0061] In some embodiments, the epoxy electrophoretic resin is a positively charged cathode epoxy resin with a solid content of 40%-45%.

[0062] In some embodiments, the PEI is analytically pure and has a weight-average molecular weight of 25,000 Da. In some embodiments, the weight-average molecular weight of the PEI can range from 10,000 to 50,000 Da. The HCl is analytically pure. The n-hexane is analytically pure.

[0063] Some embodiments of this specification provide a multifunctional protective coating prepared by the above method. The multifunctional protective coating has a thickness of 30-100 μm. The multifunctional protective coating is a multifunctional protective coating reinforced by a T / G heterojunction flat arrangement, and comprises the following components by mass percentage: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated Ti3C2T x and 0.17%-0.36% single-sided protonated GO. In some embodiments, the multifunctional protective coating is a T / G heterojunction flat arrangement enhanced multifunctional protective coating, comprising the following components by mass percentage: 20.42%-40.63% epoxy electrophoretic resin, 58.84%-79.26% deionized water, 0.21%-1.42% fully protonated Ti3C2T x and 0.11%-0.72% single-sided protonated GO.

[0064] Some embodiments of this specification provide another multifunctional protective coating prepared by the method described above. The multifunctional protective coating has a thickness of 30-100 μm. The multifunctional protective coating is a multifunctional protective coating enhanced by a flat arrangement of a G / T heterojunction, and comprises the following components, by mass percentage: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated GO, and 0.17%-0.36% single-sided protonated Ti3C2T x In some embodiments, the multifunctional protective coating is a G / T heterojunction flat arrangement reinforced multifunctional protective coating, comprising the following components, by weight percentage: 20.42%-40.63% epoxy electrophoretic resin, 58.84%-79.26% deionized water, 0.21%-1.42% fully protonated GO, and 0.11%-0.72% single-sided protonated Ti3C2T x .

[0065] In some embodiments, the mass percentage of the epoxy electrophoretic resin is 31.00%-32.00%.

[0066] In some embodiments, the mass percentage of the deionized water is 65.00%-66.00%.

[0067] In some embodiments, the fully protonated Ti3C2T x The mass percentage is preferably 0.35%-0.60%.

[0068] In some embodiments, the mass percentage of the single-sided protonated GO is preferably 0.18%-0.34%.

[0069] In some embodiments, the mass percentage of the fully protonated GO is preferably 0.36%-0.61%.

[0070] In some embodiments, the single-sided protonated Ti3C2T x The mass percentage is preferably 0.19%-0.35%.

[0071] In this specification, epoxy electrophoretic resin serves as a binder, deionized water as a diluent, and a multifunctional filler (lubricant, corrosion inhibitor, etc.) is formed by a planar arrangement of T / G or G / T heterojunctions within the epoxy electrophoretic resin. Due to the electric field, these heterojunctions exhibit a controllable order (T / G or G / T pattern) within the resin and are uniformly distributed completely parallel to the substrate. This effectively utilizes the interlayer slip characteristics, incommensurate contact properties, excellent mechanical properties, and large specific surface area of ​​the two-dimensional heterojunctions, achieving 100% utilization of the two-dimensional filler in the resin for the first time, significantly improving the friction and corrosion resistance of the epoxy resin coating.

[0072] Example 1

[0073] Preparation of raw materials:

[0074] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated Ti3C2T x 100mg, single-sided protonated GO 50mg.

[0075] Preparation method:

[0076] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0077] S2: Add 100 mg of fully protonated Ti3C2T x Add 50 mg of single-sided protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 50 mg of single-sided protonated GO to solution B and stir at room temperature for 1 h to mix evenly; obtain mixed solution A and mixed solution B respectively.

[0078] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0079] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 190°C for 100 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

[0080] In this embodiment, the fully protonated Ti3C2T x The preparation method is as follows: 2g Ti3C2T x and 2 g PEI were ultrasonically dispersed into 100 mL deionized water to obtain Ti3C2T x solution and PEI solution. PEI solution was then added to Ti3C2T x The reaction product was centrifuged and washed with ethanol and deionized water several times to remove excess PEI. 1 mol / L HCl solution was added to the reaction product and magnetically stirred at room temperature for 12 h to obtain fully protonated Ti3C2T x The reaction product was washed with ethanol and deionized water by centrifugation several times to remove the fully protonated Ti3C2T x The reaction product was freed from excess HCl and freeze-dried to obtain fully protonated Ti3C2T x .

[0081] In this example, the preparation method for single-sided protonated GO is as follows: 70 mg of PEI is ultrasonically dispersed in 25 mL of deionized water to obtain a PEI solution. 50 mg of GO is ultrasonically dispersed in 10 mL of isopropanol to obtain a GO solution. The PEI solution is poured into the bottom of a culture dish, and n-hexane solution is gradually added dropwise to the dish. A distinct stratification will appear at the interface between the two. The GO solution is then gradually added dropwise to the dish. Due to the Marangoni effect, the GO forms a complete monolayer of GO at the stratification site. The lower surface of the GO film is immersed in the PEI solution, while the upper surface is immersed in the n-hexane solution, thereby achieving amination of the lower surface of the GO sheet. The GO film is allowed to stand at room temperature for 12 hours, and the GO film at the stratification site is removed using a silicon wafer. The GO film is then washed by multiple centrifugation with ethanol and deionized water to remove excess PEI. A 1 mol / L HCl solution is then added and magnetically stirred at room temperature for 5-8 hours to obtain the product. After stirring, the product is washed by multiple centrifugation with ethanol and then freeze-dried to obtain single-sided protonated GO nanosheets.

[0082] Figure 1 Schematic diagram of the theoretical basis for the rotation of two-dimensional nanosheets in an electric field and the subsequent heterojunction formation and planar alignment; Figure 1 include Figure 1 a. Figure 1 b and Figure 1 c, where Figure 1 a shows the fully protonated Ti3C2T x and the rotation and motion trajectory of fully protonated GO in an electric field; Figure 1 b shows the self-assembly process of T / G heterojunction and G / T heterojunction in an electric field; Figure 1 c shows a tunable Ti3C2T x Multifunctional protective coating enhanced by planar arrangement of / GO heterojunction and its heterojunction microstructure.

[0083] like Figure 1 As shown in a, under the action of DC electric field, the positively charged Ti3C2T x Under the action of electric field force, it starts to move and rotate. x The shape anisotropy of the sheets and the inhomogeneity of the charge distribution along the long diameter direction, with a two-dimensional structure of Ti3C2T x The rotation is achieved by torque (M) to achieve a reasonable orientation. The two-dimensional layer is simplified to a model with a wide plane and a thin thickness, so the overall torque effect is the superposition of the torque on the plane and the thickness:

[0084] ,(1);

[0085] , (2);

[0086] , (3);

[0087] Where, , , and ,as well as , , and They are the electric field intensity, total charge, charge density, and total area in the plane direction and the electric field intensity, total charge, charge density, and total area in the thickness direction. In fact, Always better than Therefore, in the electric field, the wide plane of the two-dimensional sheet continues to move toward the cathode and rotates in the direction perpendicular to the electric field, and finally becomes fixed. The two-dimensional sheets with positive charges are very close to each other, and the same charges repel each other. The repulsive force causes the two-dimensional sheets to quickly distribute in parallel in a short time. x During the coating preparation process, the two-dimensional flakes are not affected by the electric field force and can only be scattered in the resin, and their distribution orientation cannot be controlled.

[0088] like Figure 1 As shown in b, the Ti3C2T x There are still gaps between them due to the repulsive force. At this time, the added single-sided protonated GO tends to be inserted into these gaps due to the combined effect of the electric field force and gravity (due to the double pinning of the left and right electric field forces, the fully protonated Ti3C2T x cannot enter these pores), once inserted into the pores, it will be stimulated by the positively charged Ti3C2T x The repulsive force causes it to move in the opposite direction until it is infinitely close to the Ti3C2T on the other side. x , together with the electrical resin, flows to the cathode, forming countless Ti3C2T x Multifunctional protective coating enhanced by planar arrangement of T / G heterojunction in close contact with GO.

[0089] Example 2

[0090] Preparation of raw materials:

[0091] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated Ti3C2T x 200mg, single-sided protonated GO 100mg.

[0092] Preparation method:

[0093] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0094] S2: Add 200 mg of fully protonated Ti3C2T x Add 100 mg of single-sided protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 100 mg of single-sided protonated GO to solution B and stir at room temperature for 1 h to mix evenly; obtain mixed solution A and mixed solution B respectively.

[0095] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0096] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 190°C for 100 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

[0097] In this embodiment, fully protonated Ti3C2T x The preparation method is the same as that of single-sided protonated GO in Example 1.

[0098] Figure 2 include Figure 2 a. Figure 2 b and Figure 2 c, where Figure 2 a shows the delamination phenomenon of PEI solution and n-hexane (n-hexane contains only oil-soluble shikonin, which appears red) and the spontaneous film formation of GO sheets at the delamination point; Figure 2 b shows the scanning electron microscope image of the GO monolayer film obtained by silicon wafer and its corresponding energy spectrum; Figure 2 c shows the Ti3C2T x The scanning electron microscope image of the single-layer film and its corresponding energy spectrum. Figure 2 As shown in Figure a, it can be seen that the PEI solution and the n-hexane solution are clearly separated (in order to facilitate the observation of separation, shikonin is added to the n-hexane solution. Shikonin is only soluble in oily n-hexane, but not in aqueous PEI solution). Due to the Marangoni effect, GO will be observed to form a clear film at the separation point. Figure 2 The SEM image of the GO monolayer film (b) clearly shows the complete monolayer film (composed of a monolayer GO and a few layers of Ti3C2T X Spread composition).

[0099] Figure 3The flat arrangement of the T / G heterojunction enhanced multifunctional protective coating is shown in the nano-scale slices after focused ion beam cutting (FIB cutting) and ion thinning, and the flat arrangement of the T / G heterostructure is observed using high-resolution transmission electron microscopy (HR-TEM). Figure 3 As shown, after the coating was subjected to focused ion beam cutting and ion thinning, high-resolution transmission electron microscopy observation revealed that a T / G heterostructure was formed in the coating and was arranged in a flat shape.

[0100] Example 3

[0101] Preparation of raw materials:

[0102] Epoxy electrophoretic resin 10g, deionized water 20g, fully protonated GO 100mg, single-sided protonated Ti3C2T x 50mg.

[0103] Preparation method:

[0104] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0105] S2: Add 100 mg of fully protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 50 mg of single-sided protonated Ti3C2T x Add the resulting mixture to solution B, stir at room temperature for 1 h to mix evenly, and obtain mixed solution A and mixed solution B respectively.

[0106] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0107] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 190°C for 100 minutes to obtain a multifunctional protective coating with enhanced G / T heterojunction flat arrangement.

[0108] In this example, fully protonated GO was prepared by ultrasonically dispersing 2 g of GO and 2 g of PEI into 100 mL of deionized water to obtain a GO solution and a PEI solution, respectively. The PEI solution was then added to the GO solution, and the mixture was magnetically stirred at room temperature for 24 hours to obtain a reaction product. The reaction product was washed by multiple centrifugation with ethanol and deionized water to remove excess PEI. A 1 mol / L HCl solution was added to the reaction product, and the mixture was magnetically stirred at room temperature for 12 hours to obtain a fully protonated GO reaction product. The fully protonated GO reaction product was washed by multiple centrifugation with ethanol and deionized water, and finally, freeze-dried to obtain fully protonated GO.

[0109] In this embodiment, single-sided protonated Ti3C2T x The preparation method is as follows: 70 mg PEI is ultrasonically dispersed in 25 mL deionized water to obtain PEI solution. 50 mg Ti3C2T x Ultrasonic dispersion into 10 mL of isopropanol gave Ti3C2T x Pour the PEI solution into the bottom of the culture dish, and gradually add the n-hexane solution into the culture dish. There will be obvious stratification at the interface between the two. Then, add the Ti3C2T x The solution was gradually added dropwise into the culture dish. Due to the Marangoni effect, Ti3C2T x A single layer of Ti3C2T will be formed at the delamination x The lower surface of the membrane layer is immersed in PEI solution, and the upper surface of the membrane layer is immersed in n-hexane solution to achieve Ti3C2T x The lower surface of the sheet was ammoniated. After standing at room temperature for 12 hours, the Ti3C2T x Remove the film. Wash the Ti3C2T with ethanol and deionized water several times by centrifugation. x The film was washed to remove excess PEI, and then a 1 mol / L HCl solution was added and magnetically stirred at room temperature for 5-8 hours to obtain the product. After stirring, the product was washed with ethanol by centrifugation several times and finally freeze-dried to obtain single-sided protonated Ti3C2T x Nanosheets.

[0110] Figure 4 Zeta potential values ​​for three different samples are shown. Figure 4 The original Ti3C2T x , fully protonated Ti3C2T x and single-sided protonated Ti3C2T x It should be noted that for the sake of simplicity, the fully protonated Ti3C2T x Named TH2 + , single-sided protonated Ti3C2T x Named TH + .like Figure 4 As shown, Ti3C2T x的 The surface charge of Ti3C2T is originally negative. x The Zeta potential of the material is -31.2mV. After surface protonation modification, the surface charge of the material changes from negative to positive, TH2 + The Zeta potential is 21.1mV, TH + The zeta potential of the single-sided protonated material is approximately half that of the fully protonated material. This shift in surface charge favors planar alignment during subsequent electrophoretic deposition, allowing the material to migrate toward the cathode along with the epoxy electrophoretic resin and deposit on the surface of the conductive block.

[0111] Example 4

[0112] Preparation of raw materials:

[0113] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated GO 200mg, single-sided protonated Ti3C2T x 100mg.

[0114] Preparation method:

[0115] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0116] S2: Add 200 mg of fully protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 100 mg of single-sided protonated Ti3C2T x Add the resulting mixture to solution B, stir at room temperature for 1 h to mix evenly, and obtain mixed solution A and mixed solution B respectively.

[0117] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min.

[0118] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 190°C for 100 minutes to obtain a multifunctional protective coating with enhanced G / T heterojunction flat arrangement.

[0119] In this embodiment, the preparation method of fully protonated GO and the single-sided protonated Ti3C2T x The preparation method is the same as in Example 3.

[0120] Figure 5The full X-ray photoelectron spectroscopy (XPS) spectra of three different samples are shown. Figure 5 As shown, XPS was used to further analyze Ti3C2T x Chemical element composition and content before and after modification. Ti3C2T x The basic element peaks of TH2 include F 1s (685.8eV), O 1s (532.6eV), Ti 2p (454.9eV) and C 1s (285.5eV). + and TH + The basic element peaks also include N 1s (399.5eV). The appearance of characteristic peaks in XPS and the difference in peak intensity confirm the fully protonated Ti3C2T x and single-sided protonated Ti3C2T x Successful modification.

[0121] Example 5

[0122] Preparation of raw materials:

[0123] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated GO 200mg, single-sided protonated Ti3C2T x 100mg.

[0124] Preparation method:

[0125] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0126] S2: Add 200 mg of fully protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 100 mg of single-sided protonated Ti3C2T x Add the resulting mixture to solution B, stir at room temperature for 1 h to mix evenly, and obtain mixed solution A and mixed solution B respectively.

[0127] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 100 V for 4 minutes. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 100 V for 2 minutes.

[0128] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 200°C for 120 minutes to obtain a multifunctional protective coating with enhanced G / T heterojunction flat arrangement.

[0129] In this embodiment, the preparation method of fully protonated GO and the single-sided protonated Ti3C2T x The preparation method is the same as in Example 3.

[0130] Figure 6 The flat arrangement of the G / T heterojunction enhanced multifunctional protective coating is shown in the nano-scale slices after focused ion beam cutting (FIB cutting) and ion thinning, and the flat arrangement of the G / T heterostructure is observed using high-resolution transmission electron microscopy (HR-TEM). Figure 6 As shown, after the coating was subjected to focused ion beam cutting and ion thinning, high-resolution transmission electron microscopy observation revealed that a G / T heterostructure was formed in the coating and was arranged in a flat shape.

[0131] Example 6

[0132] Preparation of raw materials:

[0133] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated Ti3C2T x 200mg, single-sided protonated GO 100mg.

[0134] Preparation method:

[0135] S1: Mix 10g of epoxy electrophoretic resin and 20g of deionized water and let it stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution is divided into two parts to obtain 20g of solution A and 10g of solution B.

[0136] S2: Add 200 mg of fully protonated Ti3C2T x Add 100 mg of single-sided protonated GO to solution A and stir at room temperature for 1 h to mix evenly; add 100 mg of single-sided protonated GO to solution B and stir at room temperature for 1 h to mix evenly; obtain mixed solution A and mixed solution B respectively.

[0137] S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 100 V for 4 minutes. Then pour the mixed solution B into the above epoxy electrophoresis tank for electrophoretic deposition at a voltage of 100 V for 2 minutes.

[0138] S4: After the deposition is completed, the residual liquid resin on the coating surface is washed away with running water, and the coating is cured at 200°C for 120 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

[0139] In this embodiment, fully protonated Ti3C2T x The preparation method and the preparation method of single-sided protonated GO are the same as those in Example 1.

[0140] Figure 7GO or Ti3C2T according to some embodiments of the present invention x Schematic diagram of the single-sided protonation process. Figure 7 As shown, 75 mg PEI was ultrasonically dispersed into 25 mL deionized water, and 50 mg Ti3C2T x Or GO is ultrasonically dispersed into 10mL of isopropanol. PEI solution is poured into the bottom of the culture dish, and 25mL of n-hexane solution with colorant shikonin is gradually added dropwise into the culture dish. The two will be clearly separated. Then Ti3C2T x Or GO solution was gradually added dropwise into the culture dish. x Or GO will form a film at the delamination. The lower surface of the membrane is immersed in PEI solution, and the upper surface is immersed in n-hexane solution to achieve single-sided amination. After standing at room temperature for 12 hours, the Ti3C2T x Remove the film or GO film. Wash the Ti3C2T with ethanol and deionized water several times by centrifugation. x The film or GO film was used to remove excess PEI, and then a 1 mol / L HCl solution was added and magnetically stirred at room temperature for 6 h to obtain the product. After stirring, the product was washed with ethanol by centrifugation several times and finally freeze-dried to obtain single-sided protonated Ti3C2T x or GO nanosheets.

[0141] Comparative Example 1

[0142] Preparation of raw materials:

[0143] Epoxy electrophoretic resin 10g, deionized water 20g.

[0144] Preparation method:

[0145] 10 g of epoxy electrophoretic resin and 20 g of deionized water were mixed evenly and allowed to stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a solution.

[0146] The solution was poured into an epoxy electrophoretic tank for electrophoretic deposition at 90 V for 3 minutes. After deposition, the remaining liquid resin on the coating surface was rinsed off with running water and cured at 190°C for 100 minutes to obtain a blank, pure epoxy electrophoretic resin coating without filler.

[0147] Comparative Example 2

[0148] Preparation of raw materials:

[0149] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated Ti3C2T x 150mg.

[0150] Preparation method:

[0151] 10g of epoxy electrophoretic resin and 20g of deionized water were mixed evenly and allowed to stand for 90min to fully mature the epoxy electrophoretic resin to obtain a matured solution. The matured solution was added with 150mg of fully protonated Ti3C2T x The mixed solution was stirred at room temperature for 1 hour to obtain a mixed solution. The mixed solution was poured into an epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90V for 3 minutes. After the deposition was completed, the residual liquid resin on the coating surface was washed off with running water and cured at 190°C for 100 minutes to obtain Ti3C2T x Composite coating with flat arrangement reinforcement.

[0152] Among them, fully protonated Ti3C2T x The preparation process is the same as in Example 1.

[0153] Comparative Example 3

[0154] Preparation of raw materials:

[0155] Epoxy electrophoresis resin 10g, deionized water 20g, fully protonated GO 150mg.

[0156] Preparation method:

[0157] 10g of epoxy electrophoretic resin and 20g of deionized water were mixed and allowed to stand for 90 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution. 150mg of fully protonated GO was added to the matured solution and stirred at room temperature for 1 hour to obtain a mixed solution. The mixed solution was then poured into an epoxy electrophoretic tank for electrophoretic deposition at 90V for 3 minutes. After deposition, the residual liquid resin on the coating surface was rinsed with running water and cured at 190°C for 100 minutes to obtain a composite coating reinforced with planar GO alignment.

[0158] The preparation process of fully protonated GO is the same as that in Example 3.

[0159] Figure 8 The evolution curves of the friction coefficient of five coatings over time are shown. Figure 8 As shown, the friction coefficient of the composite coating reinforced with planar GO arrangement stabilizes at around 0.73, indicating that the planar arrangement of pure GO in the resin does not enhance the coating's friction reduction capabilities. However, the friction coefficient of the multifunctional protective coating reinforced with planar G / T heterojunctions decreases to 0.29, a 60.27% reduction. This demonstrates that the planar arrangement of the heterojunctions in the resin significantly enhances the coating's friction reduction performance.

[0160] Figure 9 The average friction coefficient and average wear rate of the five coatings are shown. Figure 9 As shown, compared with the blank pure epoxy electrophoretic resin coating of 11.35×10 -5 mm3 / N·m wear rate, T / G heterojunction enhanced coating (2.83×10 - 5 mm 3 / N·m) and G / T heterojunction enhanced coating (2.20×10 -5 mm 3 / N·m) are greatly reduced, respectively, and have a significant anti-wear effect. This shows that the ordered flat arrangement of heterojunctions can greatly improve the tribological properties of the composite coating. This is because when the heterojunctions are distributed parallel to the coating surface (that is, perpendicular to the load application direction), T and G or G and T are in non-commensurate contact with complete lattice mismatch. This non-commensurate contact will lead to ultra-low friction, which is the theoretical basis for the super-lubricity of the current structure. The ultra-low friction of countless heterojunctions inside the coating improves the tribological properties of the multifunctional protective coating as a whole, and greatly reduces the friction coefficient of the coating. At the same time, the evenly distributed and flatly arranged heterojunctions themselves have excellent mechanical properties, which will also act as a reinforcing phase to improve the mechanical properties of the coating, so that the anti-wear performance of the coating is greatly improved.

[0161] Figure 10 The Log(Rc) values ​​of five coatings are shown. Figure 10 As shown, compared with the Log value of the blank pure epoxy electrophoretic resin coating impedance (6.03), Ti3C2T x The coating impedance Log values ​​for the composite coating enhanced by planar arrangement, the composite coating enhanced by planar arrangement of GO, the multifunctional protective coating enhanced by planar arrangement of T / G heterojunction, and the multifunctional protective coating enhanced by planar arrangement of G / T heterojunction were 7.12, 7.34, 8.10, and 8.21, respectively. This indicates that the multifunctional protective coating enhanced by planar arrangement of ordered heterojunction exhibits excellent resistance to the intrusion of corrosive media, two orders of magnitude higher than that of pure epoxy resin. This is because when the heterojunctions are distributed parallel to the coating surface (i.e., perpendicular to the diffusion direction of the corrosive medium), the two-dimensional filler utilization efficiency reaches 100%, establishing a continuous shielding layer against corrosive ions, and the protective performance approaches theoretically predicted values.

[0162] The above description describes the basic principles and main features of this specification and the advantages of this specification. It is obvious to those skilled in the art that this specification is not limited to the details of the above exemplary embodiments and that this specification can be implemented in other specific forms without departing from the spirit or essential features of this specification. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of this specification is defined by the appended claims rather than the above description, and it is intended that all changes that come within the meaning and range of equivalents of the claims be included in this specification.

[0163] Furthermore, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in the various embodiments may also be appropriately combined to form other embodiments that are understandable to those skilled in the art.

Claims

1. A tunable Ti3C2T x A method for preparing a multifunctional protective coating enhanced by a flat arrangement of a / GO heterojunction, characterized in that: include: S1: Weighing epoxy electrophoretic resin and deionized water in a mass ratio of 1:2, mixing the epoxy electrophoretic resin and the deionized water evenly and letting them stand for 90-120 minutes to fully mature the epoxy electrophoretic resin to obtain a matured solution, and dividing the matured solution into two parts to obtain solution A and solution B in a mass ratio of 9-11:4-6; S2: Adding fully protonated Ti3C2T x To the solution A, the fully protonated Ti3C2T x The mass ratio of the single-sided protonated graphene oxide to the epoxy electrophoretic resin is 1-2:100; adding single-sided protonated graphene oxide to the solution B, the mass ratio of the single-sided protonated graphene oxide to the epoxy electrophoretic resin is 0.5-1:100, and stirring at room temperature for 1 hour to obtain mixed solutions A and B; S3: Pour the mixed solution A into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 2 min, and pour the mixed solution B into the epoxy electrophoresis tank for electrophoretic deposition at a voltage of 90 V for 1 min; S4: After the deposition is completed, the residual liquid resin on the surface of the coating is washed away with running water, and the coating is cured at 170-210°C for 85-100 minutes to obtain a multifunctional protective coating with enhanced T / G heterojunction flat arrangement.

2. The method according to claim 1, wherein The fully protonated Ti3C2T x The preparation process includes: mixing equal mass of Ti3C2T x and polyethyleneimine were ultrasonically dispersed into 100 mL of deionized water to obtain Ti3C2T x solution and polyethyleneimine solution, wherein the Ti3C2T x Few-layer Ti3C2T x , the Ti3C2T x The thickness of the Ti3C2T is 0.1-1μm. x The diameter of the flakes is 20-30 μm, and the Ti3C2T x The purity of the polyethyleneimine solution is 99.99%; the polyethyleneimine solution is added to the Ti3C2T x The reaction product was centrifuged and washed with ethanol and deionized water for several times; 1 mol / L HCl solution was added to the reaction product, and the mixture was magnetically stirred at room temperature for 10-15 hours, and the mixture was centrifuged and washed with ethanol and deionized water for several times, and freeze-dried to obtain the fully protonated Ti3C2T x .

3. The method according to claim 1, wherein The preparation process of the single-sided protonated graphene oxide includes: ultrasonically dispersing polyethyleneimine in deionized water, wherein the mass volume ratio of the polyethyleneimine to the deionized water is 6-8 mg:2-3 mL, to obtain a polyethyleneimine solution; ultrasonically dispersing graphene oxide in 8-12 mL of isopropanol, wherein the mass volume ratio of the graphene oxide to the isopropanol is 45-55 mg:8-12 mL, to obtain a graphene oxide solution; pouring the polyethyleneimine solution into the bottom of a culture dish, gradually adding a n-hexane solution dropwise into the culture dish, until obvious stratification occurs at the interface between the polyethyleneimine solution and the n-hexane solution, and then gradually adding the graphene oxide solution dropwise into the culture dish; standing at room temperature for 12 hours, and removing the graphene oxide film at the stratification with a silicon wafer; washing the graphene oxide film with ethanol and deionized water by centrifugation multiple times, and adding a 1% ethanol solution with a concentration of 1% ethanol. mol / L HCl solution, magnetically stirred at room temperature for 5-8 hours to obtain a product; after stirring, the product was washed by centrifugation with ethanol for multiple times, and freeze-dried to obtain the single-sided protonated graphene oxide.

4. The method according to claim 1, wherein: In S3, the conductive block serves as the cathode in the electrophoretic deposition process. The conductive block is a conductive metal and needs to be pretreated. The pretreatment includes: sandblasting, polishing or micro-arc oxidation of the conductive block to make the roughness of the conductive block Ra∈[0.3,0.7], ultrasonic cleaning with anhydrous ethanol, wiping it clean with a dust-free cloth, and drying it to obtain the pretreated conductive block for use.

5. The method according to claim 4, wherein: The conductive metal is at least one of aluminum alloy, titanium alloy, steel or beryllium bronze.

6. The method according to claim 1, wherein The fully protonated Ti3C2T x Replaced with fully protonated graphene oxide, the single-sided protonated graphene oxide is replaced with single-sided protonated Ti3C2T x In the S4, a multifunctional protective coating with enhanced flat arrangement of G / T heterojunction is obtained.

7. The method according to claim 6, wherein The preparation process of the fully protonated graphene oxide includes: ultrasonically dispersing equal masses of graphene oxide and polyethyleneimine into 100 mL of deionized water to obtain a graphene oxide solution and a polyethyleneimine solution, respectively, wherein the graphene oxide is a single-layer graphene oxide, the thickness of the single-layer graphene oxide is 0.3-0.6 nm, the diameter of the single-layer graphene oxide flakes is 10-20 μm, and the purity of the single-layer graphene oxide is 99.99%; adding the polyethyleneimine solution to the graphene oxide solution, and magnetically stirring at room temperature for 20-28 hours to obtain a reaction product; washing the reaction product with ethanol and deionized water by centrifugation multiple times; adding a 1 mol / L HCl solution to the reaction product, magnetically stirring at room temperature for 10-15 hours, washing the reaction product with ethanol and deionized water by centrifugation multiple times, and finally freeze-drying to obtain the fully protonated graphene oxide.

8. The method according to claim 6, wherein The single-sided protonated Ti3C2T x The preparation process includes: ultrasonically dispersing polyethyleneimine into deionized water, wherein the mass volume ratio of the polyethyleneimine to the deionized water is 6-8 mg:2-3 mL, to obtain a polyethyleneimine solution; x Ultrasonic dispersion into isopropanol, the Ti3C2T x The mass volume ratio of the isopropanol is 45-55 mg:8-12 mL to obtain Ti3C2T x solution, wherein the Ti3C2T x Few-layer Ti3C2T x , the Ti3C2T x The thickness of the Ti3C2T is 0.1-1μm. x The diameter of the flakes is 20-30 μm, and the Ti3C2T x The purity is 99.99%; the polyethyleneimine solution is poured into the bottom of the culture dish, and the n-hexane solution is gradually added dropwise to the culture dish, and obvious stratification appears at the interface between the polyethyleneimine solution and the n-hexane solution, and then the Ti3C2T x The solution was gradually added dropwise to the culture dish; it was allowed to stand at room temperature for 12 hours, and the Ti3C2T x The film was fished out and the Ti3C2T was washed by centrifugation with ethanol and deionized water several times. x film; adding a 1 mol / L HCl solution and magnetically stirring at room temperature for 5-8 hours to obtain a product; after stirring, the product was washed with ethanol by centrifugation several times, and finally freeze-dried to obtain the single-sided protonated Ti3C2T x of nanosheets.

9. The method according to claim 1, wherein The epoxy electrophoretic resin is a positively charged cathode type epoxy resin with a solid content of 40%-45%.

10. A multifunctional protective coating prepared by the method according to claim 1, characterized in that: The thickness of the multifunctional protective coating is 30-100 μm. The multifunctional protective coating is a T / G heterojunction flat arrangement enhanced multifunctional protective coating, and comprises the following components by mass percentage: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated Ti3C2T x and 0.17%-0.36% single-sided protonated graphene oxide.

11. A multifunctional protective coating prepared by the method according to claim 6, characterized in that: The multifunctional protective coating has a thickness of 30-100 μm and is a multifunctional protective coating enhanced by a flat arrangement of a G / T heterojunction. The multifunctional protective coating comprises the following components by mass percentage: 31.34%-34.01% epoxy electrophoretic resin, 65.01%-67.67% deionized water, 0.33%-0.63% fully protonated graphene oxide, and 0.17%-0.36% single-sided protonated Ti3C2T x .

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